Printing machine



' 1,644,218 1927' F. w. WRIGHT PRINTING MACHINE Filed Jan. 26, 1927 //v ve/v TOR Patented Oct. 4, 1927. ii

UNITED STATES 1' j 1,644,218 PATENT OFFICE.

FRED WESLEYWRIGHT, 0F HUNSLET, LEEDS, ENGLAND, ASSIGNOR To GEORGE MANN 80 COMPANY, LIMITED, OF LARCHFIELD WORKS, LEEDS, ENGLAND.

PRINTING MACHINE.

Application filed January 26,1927, Serial No.

The invention relates to devices used for tensioning printing plates, rubber blankets or sheets of other material in different types of printing machines. I

The maindifiiculties met with in the design of devicesof the kind indicated are to secure an adequate purchase with an Figure 2 being a corresponding side ele-.

vation, while Figure 3 shows an end view of a modified form of mechanism for engaging and disengaging the rack.

Corresponding parts in the different figures are denoted by the same reference numerals.

In carrying the invention into eifect according to one form asshown in Figure 1, the blanket, sheet or the like, 2. passing round the cvlinder. 3, is secured to the usual transverse bar, 4. by any suitable means. This bar is provided with a square, 5. at one or both ends and also with a keved pinion, 6. with which a rack, 7 gears. The rack is slidable in a bracket, 8, pivoted at 9 to the cylinder end (in the oaseof rotary machines) and is provided with a lug, 10, projecting into a recess in the bracket. the lug being threaded for the reception of a fine-pitched threaded spindle. 11, having a nut. 12. at one end by which it can be turned and a pinned collar. 13. at the other end.

In the form of the invention shown, the bracket. 8. is moved into'the rack-engaging position by. a spring, 14, surrounding the rod. 15. pivoted at one end to the bracket, 8, and passing at the other end through a staple. 16. in the cylinder end. i

A screw-pin, 17 passing through a curved slot, 18, in the bracket serves to hold the latter against the cylinder end while permitting freedom of movement within the desired limits.

163,810, and in Great Britain February 1, 1926.

According to a modified form of engaging and disengaging mechanism, (see Figure 3), two parallel-faced horns or lugs, 20, 20, are provided on the bracket, 8, and between them is arranged a circulardisc, 21, with flanges, 22, pivoted eccentrically at the point, 23. Operation of the hexagon, 24, in rigid association with the disc, 21, serves both to turn the bracket, 8, into the engaging or disengaging position and automatically to lock it therein.

' In order tooperate the tensioning devices forming the subject of the present invention, the bracket, 8, with its rack. 7, is disengaged and the lug, 10, moved by means ofthe threaded spindle, 11, to the limiting .position shown in the figures. After attaching the blanket, 2. to the bar, 4, in any usual manner. the slack is taken up by operation of thesquare. 5. when the rack, 7, is reengaged and the fine adjustment actuated to give the blanket the required degree of taut-' ness.

Although certain specific forms of the invention have been described above, it will be understood that variations from such forms may be made without exceeding the scope of the invention as set forth in the claims ap ended hereto.

Having now described my invention, what I claim as new and desire to secure by Let ters Patent is 1 u 1. A blanket tensioner for printing machines, comprising in combination, a blanket carrier; a blanket bar rotatable on said carrier; means for rotating said bar; together with means for engaging and disengaging said bar-rotating means at will. 7 p, 2. A blanket tensioner for printing machines. comprising in combination. a blanket carrier; a blanket bar rotatable on said carrier: a gear coaxial with said bar and in driving relation thereto and means for opcratin said gear. said means including a means including a second :gear; together with means for carrying said second gear, said gear-carrying means being pivotally mounted on said blanket carrier about a centre other than the said centre of said blanket bar.

l. A blanket tensioner for printing machines, comprising incombinatioma blanket carrier; a blanket bar rotatable on said carrier; a gear co-axial with said bar and in driving relation thereto and means for operatingsaid gear, said means including a second gear; means for carrying said second gear, said gear-carrying means being pivotally mounted onsaid blanket carrier; together with a single instrumentality for positioning and locking vsaid gear carrying means.

5. A blanket tensioner for printing machines, comprising in combination a blanket carrier;.a blanket bar.rotatable on said-carbeing pivotally mounted on :said carrier together lwith parallel horns L011 said bracket and an eccentric operatively disposed between said horns for positioning and locking said bracket. 7

6. A blanket tens'ioner for printing machines, comprising in combination, a blanket carrier, a'blanket'bar rotatable on said car- 1101;,a.pini0n in rigid association'with said 7 bar; a bracket pivotally mounte'd on sald carrier; a rack geara'ble with said pinion and slidable on said bracket; together with means for traversing said rack in said bracket.

In testimony whereof I have signed my name to this specification.

FRED "WESLEY WRIGHT. 

